> First of all, why is this a concern? Idle threads have basically no impact on a system, so this generally isn't a concern
Idle threads have very low impact on CPU utilization, probably, if the application is well-behaved (and I expect most databases and caching layers to be well-behaved in this way). The application itself, however, will need memory and the way containers are built prevents the usual de-deplication of system libraries.
> but generally it won't even make the list of top-100 performance bottlenecks for most applications
True, but it makes the short list of "how much stuff can I run on a $100 computer", and it's one of the relatively few concerns an application operator has when they are not the application developer.
> Even if you wanted to enforce your applications sharing a postgres instance under the hood, why would you want that to be black-magic performed by the container orchestrator?
To make self-hosting much simpler. If the container orchestrator doesn't do it, what do you think should do it?
> Other stuff like DB backups just don't seem like issues docker compose users have. If you need to orchestrate across multiple nodes in order to meet your SLOs, then don't use docker compose.
The DB backups are meant for disaster recovery rather than supporting multiple nodes. I guess that's multiple nodes through time... But, yeah, I agree, docker-compose is not a good fit.
> Finally, it seems like the actual solution is significantly under-discussed. I both have tons of questions about how it's supposed to work, and I see lots of shortcomings with the parts that I do understand.
Yeah, agreed, I'll be writing other things to discuss what I think the correct solution should be. I'm curious to find out if other people have existing solutions to the problems I outlined. If it's a solved problem and I just don't know about it, that'd be better.
> I'd be interested to read an article which tried to articulate why such an opinionated API would improve SDLC-considerations over docker-compose, but I don't think that's the article I just read.
It is not, and you're right, it needs discussion.